DESIGN & ARCHITECTURE

A SACRED DUTY TO DOUBT- WILLIAM FROUDE AND J. H. NEWMAN

David Brown is Vice-President of the Royal Institute of Naval Architects and was deputy chief naval architect until his retirement. He is a leading authority on the design of warships, past, present and future and author of six books on the subject. He is writing a book about Froude at present.

William's father was Archdeacon of Totnes with a comfortable inheritance and was a
typical intelligent, hard working clergyman. William's mother, Margaret Spedding, is
said to have brought beauty, imagination and intellect to Dartington Parsonage. After
doing well at Westminster School he went up to Oriel College in 1828 to read mathematics and classics where his tutors were his eldest brother, Hurrell, and John Henry Newman, both founders of the Tractarian movement. William was to say that his two tutors were to have a great influence on his life.
Hurrell died as William graduated but he was to keep in touch with Newman until his own death in 1879. After graduating, he worked for a well known civil engineer, Palmer, moving to work on the Exeter line for I.K.Brunel in 1837. Brunel was the third great influence on Froude and they became close friends whilst he became one of
Brunel's most trusted assistants. In 1839 he married Catherine Holdsworth of a distinguished Dartmouth family and they both corresponded with Newman. In 1845 Newman moved to the Catholic church and most of his Anglican friends left him. The Froudes, however, remained close though William's views became increasingly
opposed to Newman’s. The latter was to write “I try my ideas on you as one might send an iron girder to the test house”.
Much of their debate was over the nature of proof in science and religion. Newman
maintained that while the first depended on experiment, the latter was proved by faith.
William would not accept this view, pointing out that there were too many grey areas in real life to separate science and religion. His own "faith" is summed up in a phrase which he used often - "Our sacred duty to doubt each and every proposition put to us including our own".
William retired from full time employment in 1846 to run the family estates whilst also serving as a JP, harbour commissioner and as a judge of agricultural machinery for the Bath and West. In 1857 Catherine was converted to the Catholic faith by Newman, an event which distressed William greatly and may have led to his return to active work.
That year Brunel asked for his help in the design work for the SS Great Eastern,
particularly in connection with rolling. By 1861 Froude had produced an entirely novel
theory of the behaviour of ships in waves. Though valid, it was hard to apply before
computers became available, even though Froude devised an elegant, semi-empirical
solution. Both model tests and full-scale trials proved the value of his work.
Between 1863 and 1867 Froude was busy designing and building a large house at
Chelston Cross, Torquay, now an hotel. It was much more than a residence, having a small tank for rolling experiments (now the hotel swimming pool) and very extensive workshops. At the same time he made and tested two models, SWAN and RAVEN. With these he made two very important discoveries, firstly that there was no single ideal form: SWAN was superior at higher speeds, RAVEN at lower. He also made a
series of models of each form of 3, 6 & 12ft length and showed that, if the models were run at speeds proportional to the square root of their length, then the resistance would be proportional to their immersed volume, thus establishing Froude's Law governing the resistance of ships due to wave making.
With this evidence he was able to persuade the Admiralty to fund the building of a
tank, 270 feet long, across the road from his house. This was the first of about 150 ship model test tanks, world wide, devoted to improving the form of ships, reducing their fuel consumption. Again, his work was proved on full scale, ‘The Greyhound’ being towed and her full-scale resistance measured. Both in the tank experiments and for the trials, all the novel instrumentation was designed by Froude and in many cases made by him. A vital part was his use of hard wax for the models which could be made in one day, tested the next and either altered or scrapped.
The tank formally began work in 1872 and, during the seven years until his death,
Froude advanced the science of ship - and propeller - hydrodynamics in every aspect.
His friendship with Newman continued despite an unhappy period when his son Edmund, already William's principal assistant, decided that he would like to become a priest. Eventually he was persuaded first to wait and then to work for and all too soon succeed his father in the tank.
Catherine died in 1878 and William, greatly distressed, went on a cruise to South
Africa where he caught dysentery and died in 1879 aged 69. His work lived on both for the Admiralty under Edmund and elsewhere - every tank I have been to has a portrait of Froude prominently displayed, and his name is familiar to engineers in the Froude Number.
In discussion, the conflicts of the time between the established church and
Catholicism, and between faith and science were seen to be important influences in his life. The basis on which Froude modelled physical phenomena was queried. Froude, the
lecturer said, relied mainly upon observation supported no doubt by inspiration; he was
a very intuitive man, but in establishing a particular use of models to predict full-scale
behaviour, he insisted on full-scale verification of predictions made by initial model experiments. He often went to sea, mainly in naval ships, to make observations.
The great value of working with models, when their validity had been established, was their low cost and the value of the improvements in design achieved through them.
Today much of the knowledge based on Froude's researches in the design of the forms of ships’ hulls can be applied by the use of computers, though reductions of 3 to 9% in resistance are still being achieved by the continued use of models.
David Brown